Fix PR9883. Make sure all caches are invalidated when a live range is repaired.

The previous invalidation missed the alias interference caches.

Also add a stats counter for the number of repaired ranges.

llvm-svn: 131133
diff --git a/llvm/lib/CodeGen/RegAllocBasic.cpp b/llvm/lib/CodeGen/RegAllocBasic.cpp
index 32cb622..fdc4418 100644
--- a/llvm/lib/CodeGen/RegAllocBasic.cpp
+++ b/llvm/lib/CodeGen/RegAllocBasic.cpp
@@ -309,7 +309,7 @@
     }
 
     // Invalidate all interference queries, live ranges could have changed.
-    ++UserTag;
+    invalidateVirtRegs();
 
     // selectOrSplit requests the allocator to return an available physical
     // register if possible and populate a list of new live intervals that